Gas masks are designed to keep gasses from entering the breathing space and eyes of the user. As designs have advanced, the seals around the lenses, face lines, and feeding/drinking tubes have improved.
As the seals have improved, it has become more difficult for the user to verbally communicate without the use of specialized equipment such as radio transmitters, microphones, speakers and amplifiers.
Current designs include one or more microphones connected to an amplifier connected to a speaker with the amplifier and speaker typically located outside of the mask. Such speakers project audible verbal communications from the user to those in the area surrounding the user. For example, U.S. Pat. No. 5,428,688 to Becker et al., the teachings of which are incorporated by reference in its entirety, discloses a microphone mounted inside the mask connected to an amplifier and speaker designed to be attached to the belt of a user. U.S. Pat. No. 5,371,804 to Bauer, the teachings of which are incorporated by reference in its entirety, discloses a microphone diaphragm inside the mask connected through the mask to an amplifier and speaker assembly directly mounted on the mask. According to Bauer, the disclosed voice transmission system is designed to receive a person's voice from a voice diaphragm located in the voice emitter passage of the mask, amplify the voice, and externally transmit the voice through the speaker.
U.S. Pat. No. 7,394,905 to Miller et al., the teachings of which are incorporated by reference in its entirety, describes an amplifier and speaker assembly attached to a gas mask with a manual switch to turn the circuit board of the amplifier on or off.
The communication can also occur via the radio transmitter to those in the immediate area or those outside the immediate area. U.S. Pat. No. 7,349,551 to Skillicorn et al., the teachings of which are incorporated by reference in their entirety, describes a lapel mounted microphone connected to a radio transmitter with a push-to-talk device located inside the microphone. As disclosed in FIG. 1 of Skillicorn et al., the microphone is located on the lapel and outside the mask and the user is obliged to speak audibly into the speaker outside the mask.
U.S. Pat. No. 7,457,427 to Birli et al., the teachings of which are incorporated by reference in its entirety, discloses in its background section that some masks include a communication system, such as a voice amplification system or a radio interface system. Some of these systems use microphones and amplifiers to help the user to be heard clearly outside the user's mask, either directly at the location or remotely via radio frequency transmission. Birli et al. further discloses the use of two microphones in the mask
Currently, the radio transmitter and speaker are controlled separately, leaving the operator vulnerable when attempting to operate both devices independently. For example, it is often desirable to communicate to others only via radio during military stealth operations when discovery by the enemy can be fatal. The need exists, therefore, for an improved apparatus and method for simultaneously eliminating the audible sound communication from a gas mask speaker while at the same time broadcasting the communications through a radio transmitter.